Neurobehavioral testing of chemicals: impact on recommended standards

Historically, the American Conference of Governmental Industrial Hygienists (ACGIH) has served as a major source of information on recommended safe exposure limits (Threshold Limit Values or TLV's) for chemicals most frequently encountered in U. S. industry and of known toxicologic significance. A review of the ACGIH Documentation book, which details the basis for their judgements, has indicated that 167 of the 588 chemicals for which they assigned recommended standards have, as one of their bases, direct nervous system effects. In order to increase the impact of future behavioral toxicology research on recommended standards, the neurotoxicologist can utilize certain strategies: (a) Focus on established mixtures in the environment of interest or select exposures of particular chemical classes, considering population size and severity of effect; (b) Ensure that the results of the study are referable to the expected route of exposure in the environment of interest; and (c) Select tests with face validity for non-psychologists, using reference substances. Finally, the neurotoxicologist is urged to consider effects related to safety as well as health in developing his/her research.